Changes in functional competency in the oldest old. A longitudinal study.

Changes in everyday functioning and cognitive abilities are studied longitudinally in a representative sample of the oldest old. Respondents were selected by using census records from all people aged 84, 86, 88, and 90 years old living in an area of South Central Sweden, and then were assessed at 2-year intervals. The findings show high base rates for disabilities and high incidence of cognitive and functional deficits among survivors. Mortality is associated with higher rates of disability at the previous time of assessment. Because of this increased mortality rate among disabled individuals, prevalence does not rise as much as would be expected from the high incidence. Instead, new cases of disabled are partly replacing disabled individuals who died since the previous evaluation.